Cherokee Mills didn't exist until after the Civil War. This incident took place at the McConnell's house, now under Lake Alatoona. Involved Lt. J.J. O'Neal's detachment from Company L, 6th Georgia Cavalry, Iverson's Brigade. Cherokee Advance, April 15, 1887 may be the original story.
Amazing! My GGGwhatever grandfather was in the Sixth Georgia Cavalry and may well have been on the scene. Beginning in summer of 1863, the Sixth frequently had the misfortune of facing soldiers from Wilder's Brigade. To add a bit of irony, he was from Cherokee County in Alabama but his company was formed in Rome, Georgia not too far from this incident. That's the thing about cavalry service: these guys were seldom involved in big battles but were in countless patrols and ambushes in between that were every bit as deadly.